SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2211fa9da4236c3338adf22cb073edc0f920d13d3143b90702d11891402fe79' 
  AND token = 'G+IbgaFD3G4kAUnsihlYa5imsKrSSdG20kMbnjMLV9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}